Astronomy and Astrophysics – Astrophysics
Scientific paper
1997-01-17
"The Physics of LINERs in View of Recent Observations," 1996, eds. M. Eracleous, A. Koratkar, C. Leitherer, and L. Ho, 70
Astronomy and Astrophysics
Astrophysics
20 pages, 18 postscript files imbedded as 11 figures
Scientific paper
We present the results of ASCA observations of a heterogenous sample of 15 spiral galaxies. 8 are LINERs or low-luminosity AGN (LLAGN), 5 are starburst galaxies and 2 are normal spiral galaxies. We find that in all cases the ASCA spectra can be described by a canonical model consisting of a power-law with a photon index ~ 1.7-2.0, plus a soft optically thin emission component with kT ~ 0.6-0.8 keV. The implied element abundances are often sub-solar. The soft component is usually extended and the nuclear, point-like emission is sometimes absorbed by column densities in the range log nH ~ 21-23 cm-2. The relative luminosities of the soft and hard components vary from galaxy to galaxy. For the LINERs, the 2-10 keV luminosity of the hard component is typically log L ~ 40-41 ergs/s whereas the 0.5-2.0 keV luminosity of the soft component is typically log L ~ 39-40 ergs/s. For starbursts, the 2-10 keV luminosity of is log L ~ 39-40 ergs/s, somewhat lower than the corresponding luminosity of most of the LINERs in our sample. The hard component is similar to the observed X-ray spectra of quasars and also to the intrinsic X-ray spectra of classical Seyfert galaxies. Most of the galaxies in our sample exhibit no significant (dI/I > 20%) short-term variability (with timescales of a day or less) whereas long-term variability is common. We present a case study of the LINER M81 in detail where there is evidence of large-amplitude (dI/I ~ 70%) variability over several weeks. There is also clear evidence for a broad, complex Fe-K emission line which is compatible with an origin in an accretion disk viewed at ~ 40 deg. These results suggest a strong connection between classical AGN, LINERs, and starburst galaxies.
Ptak Andrew
Serlemitsos Peter
Yaqoob Tahir
No associations
LandOfFree
X-ray Observations of LINER and Starburst Galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with X-ray Observations of LINER and Starburst Galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and X-ray Observations of LINER and Starburst Galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-608014